Appendix H. Interface Emulation Compatibility; Printer Interfaces; Parallel And Serial Interfaces; Multisource Timeout - Genicom GEK-00027C User Manual

APPENDIX H. INTERFACE EMULATION
COMPATIBILITY

PRINTER INTERFACES

Parallel and Serial Interfaces

Multisource Timeout

IEEE 1284 Bi-directional Parallel Port

5180 User's Manual
The printer has bi-directional IEEE-1284, RS-232 serial and RS-422
balanced voltage serial interfaces as standard. The RS-232 and RS-
422 options share the same 25-pin, D connector. An additional two
optional interfaces may be added, which can include Ethernet, IBM
Twinax/Coax, Data Products Long Line, Data Products Short Line,
and Legacy Centronics. See Figure 2-2 on page 1 for the location of
the optional interface slots.
All of the installed interfaces are active in the default Multsource
setting of the Select I/F menu (under Set Up Menu | I/F Settings).
The exception is the necessary selection of either RS-232 (default) or
RS-422 options as the serial interface. If desired, selecting only one
installed interface causes the printer to ignore other data sources
that may be connected to the printer.
Each interface has its own input buffer. If the filters are enabled,
each enabled filter represents 16K bytes of additional buffer capacity
in series with the associated interface buffer.
In the Multisource setting, data is printed from the first port at which
data is received. When no further data is received at that port, after a
period of seconds, other ports are serviced on a first-come, first-serve
basis. This period of time may be adjusted via the Delay Seconds
option located in Set Up Menu | I/F Setting | Multisource. See page
71 for instructions to modify this setting. The default is three
seconds.
The parallel port is IEEE 1284 nibble-mode compliant. The standard
minimum bi-directional function is used to report make and model to
1294-compliant hosts. A plug-and-play system such as Windows®
uses this information to check for the appropriate printer driver. To
a non plug-and-play operating system, such as a traditional
Centronics host, the parallel port appears to be a traditional
Centronics port. The protocol is Busy-by-Character and ACK during
busy. The input buffer size is fixed at 8.2K bytes, but any filters
which have been enabled and associated with this port represents
16K bytes additional buffer capacity per filter.
Historically, line printers enabled a multitude of parallel-port user-
adjustments. IEEE-1284 compliance, however, imposes constraints.
For this reason, the only characteristic of this port, which is user-
controlled is whether the nFAULT signal is true on a paper-out
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